Microfabricated rotary motion wobble motor and disk drive incorporating

Abstract

A motor based on the wobble motor provides pure rotary motion and can be used as a spindle motor for very small disk drives. The primary components of the motor are fabricated using thin film processes. The rotor has inner and outer rings that are interconnected by flexible members, such as semicircularly-shaped spring elements, with the rings and flexible members being formed of the same material. The rotor resides within the wobble motor stator elements that are circumferentially spaced on a substrate. The inner rotor ring is supported by a bearing structure that may be a ball bearing assembly or a pin bearing comprising a post and a restraining cap. The outer rotor ring functions as the wobble motor rotor and rolls around the inside of the stator as the stator elements are sequentially electrostatically activated. The flexible members act as a transmission to convert the wobble motion of the outer rotor ring to pure rotary motion of the inner rotor ring. The motor can function as a disk drive spindle motor by attachment of a data recording disk to the inner rotor ring and use of appropriate control circuitry to drive the motor at constant speed. The disk drive actuator may be attached to the same substrate that supports the stator elements. The stator elements, the rotor, and the bearing assembly may all be fabricated on a suitable substrate using thin film processes, without the necessity of assembly of separate components.